Numerous flow sensors are believed to be understood from the related art for detecting the flow of a fluid medium. These types of ultrasonic flow sensors are understood to detect, for example, a mass flow, a volume flow, or a velocity of the fluid medium, for example in a flow tube. Two or more ultrasonic converters are usually used, which are situated in the flow offset relative to one another, longitudinally with respect to the flow of the fluid medium, and which are able to exchange ultrasonic signals. Based on differences in the propagation times of the ultrasonic signals having a component in the flow direction and having a component against the flow direction, the flow rate and/or other variables which characterize the flow may be deduced.
One example of this type of ultrasonic flow sensor (which within the scope of the exemplary embodiments and/or exemplary methods of the present invention described herein may also be modified according to the exemplary embodiments and/or exemplary methods of the present invention) is discussed in DE 39 41 544 A1. This publication discusses an ultrasonic flow meter having multiple reflections of the ultrasonic signals between the ultrasonic converters. This results in a W-shaped ultrasonic path in the measuring tube, which offers the advantage of a longer sound path and a converter installation that is flush with the wall.
However, one disadvantage of these reflection devices is that reflection surfaces, several of which are understood to be required in DE 39 41 544 A1, may reduce the robustness of the system. In particular, the reflection surfaces, exactly three of which are required in the described configuration, are sensitive to vibrations, may influence the flow conditions, and are susceptible to contamination and the associated changes in the reflectivity, or to thermal distortion.